The present invention relates to flow matching valves and more particularly to such a valve which facilitates and simplifies the construction of hydraulic systems.
In the above-identified parent applications, there is described a flow matching control valve in which a piston is axially slidable within a sleeve, the sleeve and the piston having a first pair of mating valving surfaces and, axially spaced from the first pair, a second pair of mating valving surfaces, the two pair of valving surfaces being matched to open in synchronism. Passageways in the piston connect one pair of valving surfaces to one end of the piston and connect the other pair of valving surfaces to the other end of the piston. One end of the sleeve incorporates a valve seat and a valving member is provided which can mate with and close off the seat. The piston includes a portion which engages the valving member to lift it off the seat substantially at the same time that the mating valving surfaces open. In the sleeve, passageways are provided which connect each of the pairs of valving surfaces to respective drain ports.